From f9b34a13becc090b5db8584973b7e2860497843c Mon Sep 17 00:00:00 2001
From: Bernd Kuhls <bernd.kuhls@t-online.de>
Date: Sat, 20 Jan 2018 23:07:09 +0200
Subject: [PATCH xserver 2/8] configure.ac: Fix check for CLOCK_MONOTONIC

Discover monotonic clock using compile-time check

monotonic clock check does not work when cross-compiling.

Upstream-Status: Denied [Does not work on OpenBSD]
Signed-off-by: Jussi Kukkonen <jussi.kukkonen@intel.com>

Original patch follows:

When xorg-xserver is being cross-compiled, there is currently no way
for us to detect whether the monotonic clock is available on the
target system, because we aren't able to run a test program on the host
system. Currently, in this situation, we default to not use the
monotonic clock. One problem with this situation is that the user will
be treated as idle when the date is updated.

To fix this situation, we now use a compile-time check to detect whether the
monotonic clock is available. This check can run just fine when we are
cross-compiling.

Signed-off-by: David James <davidjames at google.com>

Downloaded from
https://github.com/openembedded/openembedded-core/blob/master/meta/recipes-graphics/xorg-xserver/xserver-xorg/0001-configure.ac-Fix-check-for-CLOCK_MONOTONIC.patch

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
---
 configure.ac | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/configure.ac b/configure.ac
index 88d687d56..76c8baa6f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1052,19 +1052,16 @@ if ! test "x$have_clock_gettime" = xno; then
         CPPFLAGS="$CPPFLAGS -D_POSIX_C_SOURCE=200112L"
     fi
 
-    AC_RUN_IFELSE([AC_LANG_SOURCE([
+    AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
 #include <time.h>
-
-int main(int argc, char *argv[[]]) {
-    struct timespec tp;
-
-    if (clock_gettime(CLOCK_MONOTONIC, &tp) == 0)
+#include <unistd.h>
+int main() {
+#if !(defined(_POSIX_MONOTONIC_CLOCK) && _POSIX_MONOTONIC_CLOCK >= 0 && defined(CLOCK_MONOTONIC))
+        #error No monotonic clock
+#endif
         return 0;
-    else
-        return 1;
 }
-    ])], [MONOTONIC_CLOCK=yes], [MONOTONIC_CLOCK=no],
-       [MONOTONIC_CLOCK="cross compiling"])
+]])],[MONOTONIC_CLOCK=yes], [MONOTONIC_CLOCK=no])
 
     LIBS="$LIBS_SAVE"
     CPPFLAGS="$CPPFLAGS_SAVE"
-- 
2.16.1

